A conventional projector system for obtaining an image over a large screen using a liquid crystal, is described in Japanese Patent Laid Open No. 159120/87. FIG. 2 is a schematic construction diagram of such a conventional liquid crystal projector system wherein light emitted from a light source 1 is condensed by a lens 2 and then an image formed on a liquid crystal panel 3 by the light beam from the lens 2 is projected enlargedly onto a screen 5 through a projection lens 4. This system enables a planer image as large as 100 inches in the length of a diagonal line. It is noted that the light source 1, lens 2, liquid crystal panel 3 and projection lens 4 are generally contained in a single housing which also contains a cooling device and thereby heat and noise are generated in such housing.
As a related conventional projector, there is known an all sky projector using a planetarium as a structural building, for example, such as that described on page 95 of Gendai Camera Shinsho No. 76--Introduction to the Science of Lens (Last Volume)--by Toshinobu Ogura (publisher: Asahi Sonorama Co.). Further, there is described a liquid crystal projector system using a fish-eye lens, in Japanese Patent Laid Open No. 80239/91. According to this technique, the fish-eye lens forms a part of the projector body and is disposed proximate to the head of the viewer whereby, the viewer is provided with more realistic images having a sense of presence.
For obtaining an image over a large screen of 100 inches in diagonal length with the above-mentioned conventional liquid crystal projector systems, it is required to provide a sufficient projection distance on the order of 3 to 4 meters from the projection lens 4 to the screen 5. Consequently, when the system is in use, it is necessary to provide a large space almost equal to one six-mat room of the Japanese standard measurement or approximately 10 m.sup.2.
On the other hand, in order to use such a large screen projector system as a game system for the pleasure of many people, it is necessary to make the system into a compact system requiring only a small projection space which permits indoor installation as in a so-called game center. Besides, it is desired that the system permit one or more persons to enjoy it and that the system provide variety of amusement to many people through the transmission of many pieces of information.
For an image viewer who plays a game, it is necessary to ensure an appropriate space and improve comfortableness so that the viewer does not have a sense of oppression or unpleasant feeling. In the case of an all sky projector used in a planetarium, for example, where a sufficient space for the viewer is ensured, since the planetarium is a structural building, such a projector system is not easy to manufacture industrially and requires a large amount of space not suitable for the game usage.